Lighted pushbutton assembly



July 23, 1968 J. J. DENNISON LIGHTED PUSHBUTTON ASSEMBLY 4 Sheets-Sheet1 Original Filed Sept. 22, 1965 INVENTOR.

JOHN JOSEPH DENNISON 3 Q N mm mm mw Q vw IF. .fnIll I 1 mm 8 UN mural 1N- mm 2 Q mm mm Q ATTORNEYS y 1968 J. J. DENNISON 3,394,403

LIGHTED PUSHBUTTON AJSEMBLY Original Filed Sept. 22, 1965 4 Sheets-Sheet2 JOSEPH DENN ISON ATTORNEYS July 2 1958 J. J. DENNISON LIGHTEDPUSHBUTTON ASSEMBLY 4 Sheets-Sheet 3 Original Filed Sept. 22, 1965INVENTOR. JOHN JOSEPH DENNISON ATTORNEYS July 23, 1968 J. J. DENNISONLIGHTED PUSHBUTTON ASSEMBLY 4 Sheets-Sheet 4 Original Filed Sept 22,1965 FIG. 8

FIG. 7

ATTORN EYS INVENTOR JOHN JOSEPH DENNISQN A 3 3 r 2 O00 5 44%? UnitedStates Patent 3,394,403 LIGHTED PUSHBUTTON ASSEMBLY John J. Dennison,Cheshire, Conn., assignor to Maxson Electronics Corporation, GreatRiver, N.Y., a corporation of New York Continuation of application Ser.No. 489,292, Sept. 22, 1965. This application July 6, 1967, Ser. No.651,631

14 Claims. (Cl. 200-167) ABSTRACT OF THE DISCLOSURE A lighted pushbuttonswitch having a movable electrode section and spaced contacts. Theelectrode section is ;moved by a slidable sleeve. The sleeve operates amechanism which causes the snap action of the switch from one contact tothe other and vice versa. Upon removal of actuating forces on thepushbutton the latter returns to its rest position.

This application is a continuation of a copending application of John J.Dennison, Ser. No. 489,292, filed Sept. 22, 1965 and entitled LightedPushbutton Switch.

This invention relates to electric switches for controlling electriccircuits and more particularly to an illuminated pushbutton switchdevice in which the illumination is incorporated into and associatedwith, the switch structure itself.

In the control of electric circuits it is desirable to provide switcheswhich are compact and reliable and which operate with a quick or snapaction to engage and disengage electrical contacts which complete orbreak the electrical circuits in which the switch operates. In the caseof a pushbutton switch it is also desirable that illumination means heprovided so that the switching state of the switch can be readilyascertained by the operator.

It is also desirable to provide, in an illuminated pushbutton snapaction switch, a means for mounting the illumination means so that theillumination means remains stationary when the pushbutton is operatedthereby providing greater reliability and resistance to shock andvibration which would tend to shorten the life expectancy of theelectric bulb associated with the illumination means.

Another reason for providing for a stationary illuminating means is thatthe electrical contacts connected to the bulb lamp terminals need not bemovable or flexible.

Another feature which would be desirable in an illuminated pushbuttonswitch would be the provision of means for retaining the pushbutton lampassembly within the switch, and the provision of a simple means forremoving the pushbutton lamp assembly and for reinserting the pushbuttonlamp assembly to replace the light bulb without removing the entireswitch assembly from its housing.

It is an object of this invention to provide a compact, rigid,illuminated pushbutton snap action switch.

It is a further object of this invention to provide an illuminated pushbutton switch in which the illumination means is stationary with respectto the pushbutton means.

It is a further object of this invention to provide an illuminatedpushbutton snap action switch in which the pushbutton lamp assembly maybe readily removed from the switch housing so that the lamp can bereplaced without the removal of the entire switch assembly from itshousing.

A further object of this invention is the provision of an improvedplunger or pushbutton operated electric switch of compact size providingfor snap action of the switching contacts and having an illuminatedpushbutton ice for ready identification of the state of the switchingdevice.

The illuminated pushbutton snap action device of the invention includesan illumination means disposed between a snap action switch and apushbutton and also includes a sleeve which operatively connects thepushbutton and the switch. Actuation of the pushbutton causes actuationof the switch. The switch is a generally cylindrical body having switchcontact members at one end and a pushbutton at the other. The switch isadapted for mounting in an opening in a panel. The switch can be mountedon the panel by either a threaded nut or by projecting spring fingerswhich connect the switch body to the panel housing. The pushbutton andsleeve operate to depress a plunger or a pawl which in turn engages anabutment of a cam causing a rotary motion of the cam from one fixedposition to a second fixed position. The rotary action of the cam movesone end of an extension spring to its overcenter position therebytransferring a contact which is part of a blade, from one position to asecond position with a positive snap action. Upon removal of the appliedactuator force on the pushbutton a spring returns the pushbutton, thepawl guide and the pawl to the original free position making it readyfor subsequent cycles of alternate on-ofi pushbutton operation.

The operation of the unique snap action switching con struction and theunique lamp and button retention device which permits ready replacementof the lamp and pushbutton, as well as other features and objects ofthis invention, will become more apparent from a reading of thefollowing specification and appended claims studied in conjunction withthe drawings, in which:

FIG. 1 is a longitudinal sectional view of an illuminated pushbuttonswitch according to the present invention;

FIG. 2 is a partly sectional view of the switch body taken along line2-2 of FIG. 1;

FIG. 3 is a side longitudinal sectional view of an illuminatedpushbutton snap action switch according to the present invention;

FIG. 4 is an enlarged detail sectional view of the view shown in FIG. 3showing the pawl guide moved to one of its operating positions;

FIG. 5 is an exploded perspective view of a switch according to thisinvention showing the basic elements of the switch construction;

FIG. 6 is an exploded perspective view showing the elements of the snapaction switch;

FIG. 7 is an end view of the switch according to this invention showingthe electrical contact end of the switch;

FIG. 8 is a cross sectional view of the switch along the lines 88 ofFIG. 4;

FIG. 9 is a cross sectional view of the illuminated pushbutton switchtaken along lines 99 of FIG. 4;

FIG. 10 is a cross sectional view of the illuminated pushbutton switchtaken along lines 1010 of FIG. 4;

FIG. 11 is a cross sectional view taken across lines 11-11 of FIG. 3;and

FIG. 12 is an example of one possible wiring connection.

Referring now to the drawings in which similar elements are identifiedby the same numerals, there is provided an outer cylindrical housing orcasing 11, having a forward threaded portion 12 (FIG. 2). A decorativebezel 13 has mounting tabs 14 (FIG. 2) extending therefrom. The bezel 13is mounted on the forward portion of the electrically non-conductivehousing 11 by bending the tabs 14 into the recessed portion 15 of thehousing 11. A mounting nut 16 (FIG. 3) is threaded on the forwardportion of the housing in order to mount the switch assemly on thepanel, fragmentarily illustrated in action in FIG. 3. A lamp 17, whichis mounted in lamp base 18,

having an electrical terminal at the bottom end thereof, is mountedwithin the housing in a manner described below.

At the rear end of the switch is a tubular member 21, which contains theelements of the switching mechanism, and a base member 22, made of aninsulating material, which is placed on the rear end of the structure.The housing 11, which contains electrical contacts 23 and 23b having endportions 23a which extend from the switch housing when the switch isassembled, is disposed around the tubular member 21. The lamp 17 isilluminated when a voltage appears across terminals 23, due to theoperation of the switch, thereof. Thus the lamp may serve to indicatethe position of the switch contacts.

At the forward end of the switch housing 11, pushbutton 24, formed froma transparent light transmitting material, is slidably disposed in theopening 25 of the bezel 13, and is placed over the lamp assembly 17, 18.The pushbutton and lamp assembly are retained in the housing 11 in amanner described below.

The switching mechanism is inserted through the rear end of the switch,and retaining base member 22 is placed thereover and fixed to thehousing as shown in FIG. 8 by means of a pair of pins 25 each of whichextend through aligned holes 26 in parts 11 and 21, and, as shown inFIG. 8, into an aligned recess 27 formed in the base member 22. When theswitch is so assembled, the ends of two stationary switch terminals 28and the end portion 29a of a stationary center electrode 29 extend fromthe rear portion of the switch.

Within the switch housing is a switching mechanism which includestension spring 30, a blade 31 bearing on one end a common contact 33 andconnected to spring by the end hook portion of the spring being placedthrough the slot 32 of blade 31. The blade 31 is pivoted to the centerelectrode 29 by resting in an indentation in the inner end of the centerelectrode and is held firmly in place by the tension spring 30. (SeeFIGS. 4 and 6.) A hollow cam 34 carries a transverse shaft 35 in itsinterior and is also located within the switching unit. As seen best inFIG. 3, the rotatable cam 34 is provided with trunnions 42 which aremounted in cutouts 51 which are formed in the ears of common contact 29.These cutout portions are aligned transversely to the axis of thetubular member 21. The other end of tension spring 30 is secured to theshaft 35 to place the trunnion axis intermediate the point of attachmentof each end of the spring to best form a snap action toggle. Thistension spring thus serves to hold the tiltable member 34 with itstrunnions in the cut-outs or bearings 51 and also to hold the end of theblade 31 in its recess in the center electrode. In addition the springcauses the member 34 to take a position to one side or the other of aposition in which a straight line interconnecting the points ofattachment of the spring intersects the trunnion axis. A pawl guide 38having extensions 39 which engage grooves 40 within the switch body 11,co-operates with the pushbutton to cause axial motion of a pawl 40a. Thepawl is held against the pawl guide by a compression spring 41 thuscentering the pawl, when the pushbutton is not depressed, andmaintaining the pawl in alignment with the axis of the housing. Thecompression spring 41 also exerts a returning force upon the pushbuttonassembly. The pawl causes the cam 34 to rotate to effect the snap actionswitching in a manner which is described below.

When the unit is in its assembled position the pushbutton 24 and thelamp assembly 17, 18 are retained in the housing 11 by means of thedetent 43 at the inner end of the resilient spring member 23. The detent43 engages the flange 19, on the lamp base 18, retaining both thepushbutton 24 and the lamp base 18 connected to the housing 11. Theretention prevents movement of the lamp while allowing the axial motionof the pushbutton 24 to actuate the switch mechanism in a mannerdescribed below. An over-travel stop 44, located on the interior ofhousing 11, limits the amount of button travel and protects the switchmechanism from being damaged by excessive button travel.

In operation, the hollow pushbutton 24 is depressed, so that theelongated side portions 45 of the pushbutton contact the pawl guide 38at extensions 39. The pawl guide, under the urging of the pushbutton 24,moves axially when acted upon by the pushbutton 24. The pawl 40a in itsfree position remains parallel to the axis of the pawl guide 38 and isheld in this position in the pawl guide recess 46 by the force exertedby compression spring 41 on bar 37 of the pawl. The pawl remains seatedin the recess 46 (FIG. 4) until further motion of the button causes theend edge 48 of the pawl to engage the inclined surface 49 of the cam 34.Still further movement of the pushbutton causes the pawl to rotate orpivot within guide recess 46 by the action of the pawl against theinclined surface 49 of the cam until the end edge 48 of the pawl engagesthe cam abutment 3412.

Additional travel of the pushbutton in combination with thecorresponding movement of the pawl imparts a rotary motion to the cam 34from one pre-determined end position to a second pre-d-etermined endposition. The rotary action of the cam moves the end of the tensionspring 30 (which is aflixed to shaft 35) so that the end of the tensionspring moves to its over-center position thereby transferring electricalcontact 33, which is affixed to the end portion of blade 31, from oneend position to a second end position with a positive snap action. Uponremoval of the applied actuator force on the pushbutton the returningspring 41 exerts the necessary force to return the button, pawl guideand pawl to the original free position making the switch ready forsubsequent cycles of alternate, on-otf pushbutton operation.

The above operation and structure can be modified so that switchingaction can be changed to a momentary action switch where the switchcontact 33 transfers from one end position to a second end position andupon release of the applied force on the pushbutton the contact 33transfers back to its original position. This modification isaccomplished by changing the relationship of the over-center position ofblade 31 with respect to the location of shaft 35 and the pivot axisformed by trunnions 42 of the cam 34. This relationship is such that theangular movement of the shaft 35 (with spring 30 attached thereto) aboutthis pivot axis 42 must be restricted to a pre-determined position toprevent shaft 35, pivot axis 42, and the blade 31 over-center positionfrom being co-linear while permitting the blade 31 and the tensionspring 30 to pass through the over-center position, transferring contact33 from one position to a second position. Upon release of the appliedforce on the button the contact 33 returns to its original position.

An important feature of this invention is the unique lamp and buttonretention device that permits easy and fast replacement of the lamp andpush button without the aid of special tools and without the necessityof disassembling the whole switching device when it is desired toreplace the lamp. At the same time this unique construction permitsactuation of the pushbutton without a resultant motion of the lamp.

The pushbutton 24 is formed as an elongated tubular member having aclosed end 50 serving as a pushbutton surface, and having slots throughthe walls thereof forming skirts and an internal shoulder. The lamp base18 which has a flange 19 is inserted from the rear of the pushbutton,forcing the skirts apart. As shown best in FIG. 1 the lamp is assembledin the pushbutton by inserting the lamp and lamp base into the bottomopening 53 of the pushbutton until the flange 19 of the lamp base comesinto contact with detents 54. The additional force applied to the bottomof the lamp flange 19 in combination with detents 54 deflects theflexible member or skirts outward permitting the flange 19 to enter intothe recess 56 of the button thereby capturing the lamp in the button. Adirect pull on the lamp flange is required to accomplish the reverseoperation of removing the lamp assembly from the pushbutton. Thepushbutton contains two longitudinal grooves 52 spaced 180 degrees apartand formed in the outside of the pushbutton. The housing 11 alsocontains two mating lugs 55 which are located on the inside of thehousing. To assemble the button and lamp into the housing assembly, thebutton is inserted into the front opening in the housing until thebottom of the button stops against the top surfaces of the lugs. Thebutton is then manually rotated until lugs 55 and grooves 52 are in linewith one another thus permitting lugs 55 to enter the grooves 52 in thepushbutton. This prevents the button from rotating and the button isthen guided until the inclined planes 58 of the button grooves 52 comeinto physical contact with lugs, whereupon the applied button forceacting through the inclined planes 58 against the housing lugs 55imparts a rotary motion to the button 24 thereby permitting lugs 55 toenter the upper portion of grooves 52, permitting the button to travelaxially within the housing. Any additional force applied to the buttonwill permit flange 19 of lamp base 18 to engage and overcome forcesexerted through detent 43 thereby capturing both the lamp and button inthe housing assembly. Detent 43 yieldably prevents lamp movement to theleft, and element 23b engages contact 20 to prevent lamp movement to theright, as viewed in FIGS. 3 and 4, while axial motion of the button tooperate the switch mechanism is unrestraining. Upon release of theapplied actuator force the button will move to its installed positionremaining captured to the housing assembly.

The a butments 62 in the bottom grooves 52 and detents 54 prevent thebutton 24 from flying out of the unit when the button is depressed andsnap released. To remove the button and lamp from the housing a directpull on the projecting portion of the button is required to over-comethe retaining force of detent 43. Upon release of the detent a slightrotary motion of the button is required to clear abut-ments 62 forremoval of the button. With the button removed from the unit a directpull on the lamp flange 19 will remove the lamp assembly from thebutton. A new lamp assembly may then be inserted in the pushbutton bypushing it in a sufficient distance to eflect engagement of the flangeon the lamp base with the shoulder and thus when the button and lamp areinserted in the housing they are retained by the base engagement withlamp contact 23b. The lamp assembly thus retains the pushbutton in placeand yet the lamp assembly does not move axially upon depression of thepushbutton.

The switch assembly may either be mounted on the panel by a conventionalthread shoulder and nut type of mounting arrangement or by a set ofresilient spring fingers which are disposed around the perimeter of thehousing 11. The switch housing is inserted into the panel mounting hole.Spring fingers would be deflected inwards thereby permitting entry ofthe switching unit into the housing hole. When the flange of the switchhousing contacts the top surface of the mounting panel, the springfingers would then be deflected against the mounting panel to providethe necessary lateral force against the sides of the mounting hole toretain the unit to the panel.

It will be seen that with the structure described above the pushbutton2-4 has a front exposed end which is at least in part light-permeable sothat when the lamp 17 is illuminated the light therefrom will be visibleto the operator. While in the illustrated example the material of thepush-button is made of any suitable color, while being transparent, itis perfectly possible to have an opaque push button provided simply withan opening through which the light of the lamp 17 will be renderedvisible to the operator. The elongated housing 11 guides the pushbutton24 for longitudinal movement and a pair of retaining means are formed bythe above-described structure and are respectively carried by thehousing 11 and the pushbutton 24 for yieldably retaining the lampassembly 17, 18 at a given position within the housing 11 duringreciprocation of the push button 24 and for retaining the lamp assembly17, 18 within the hollow pushbutton 24 until after the latter is removedfrom the housing 11, at which time the other of the retaining means canyield to permit removal of the lamp assembly 17, 18 from the interior ofthe pushbutton 24. Thus, it will be seen that one of these retainingmeans is formed by the elongated electrically conductive members 23 and23b. These members of course, form part of the electrical circuit forthe lamp assembly 17, 18. Thus it will be seen that the elongatedelectrically conductive member 2311 engages the contact 20 of the lamp17 while the elongated member 23 engages the lamp base 18. The yieldabledetent 43 of the member 23 prevents movement of the assembly 17, 18 tothe left while the member 23b engages contact 20 to prevent movement ofthis assembly to the right, as viewed in FIGS. 3 and 4, and in this waythese elements 23 and 23b form one of the pair of yieldable retainingmeans yieldably retaining the lamp assembly 17, 18 at the pozitionthereof illustrated in FIGS. 3 and 4.

The other of the retaining means is of course formed by the springyskirt or wall portions of the pushbutton 24 which is respectivelyprovided with the projections 54 which form the detents engaging theflange or projection 19 of the lamp base 18 for retaining the assembly17, 18 Wi'hin the hollow pushbutton 24, as indicated in FIG. 1. Thus,with this. construction the retaining means 23, 23b carried by thehousing 11 will maintain the assembly 17, 18 in the illustrated positionduring reciprocation of the pushbutton 24, and the housing 11 itselfprevents yielding of the springy wall portions of the pushbutton 24which carry the detents 54 so that while the pushbutton 24 is in thehousing 11 the detents 54 cannot yield to permit displacement of theassembly 17, 18 out of the hollow pushbutton 24. However, with a strongenough pull the operator can cause the detent 43 to yield so that theentire pushbutton together with the assembly 17, 18 will be displacedout of the housing, and then the springy skirt or wall portions of thehousing 24 can yield to permit displacement of the lamp assembly 17, 18out the pushbutton when, for example, it is necessary to replace a lamp17. Of course, the parts are reassembled through the reverse of thesesteps.

Furthermore, it will be noted that with the structure of the inventionthe center electrode 29 has a bearing formed by the elongated V-groovewhich receives the free end portions of the blade 31 to support thelatter for tilting movement. This V-groove is of course situated in theplane through which the left end of the snap-spring 30 must pass duringthe over-center action of the structure to snap the blade 31 between thestationary contacts 28. When the parts are at rest the pawl tmeans 40ais situated in the rest position shown in FIG. 3 where this pawl also issituated in the plane in which the V-groove which receives the blade 31is located. The central electrode 29 in addition has a bearing meansformed by the recessed ear portions which receive the trunnions 42 so asto define a pivot axis for the hollow cam means 34 provided with theprojections 34a alternately situated in the path of movement of thepawl. Of course, the shaft 35 is carried by and extends across thehollow interior of the cam means 34 to receive the left end of thesnapspring, 30, which is hooked at its right end onto the blade 31, andit is to be noted that it is the movement of the axis of the shaft 35 toone or the other side of the plane which includes the pivot axis of thecam 34 and the tilting axis of the blade 31 which produces theovercenter action causing the blade 31 to be snapped between thestationary contacts 28.

The guide means 38 is formed with the elongated V-rib 46 whose crest isalso situated in this latter plane and this rib is received in theelongated V-groove at the left end of the paw-l, as viewed in FIGS. 3and 4, this V-groove extending along the transverse pawl bar 37 againstwhich the spring means 41 presses to yieldably maintain the pawl meansin the rest position shown in FIG. 3, and of course it is this spring 41which acts not only on the pawl means, but also on the guide 38 andthrough the latter pushbutton 24 to return the latter to its outerinitial position.

The electrical structure of the switch can be used for many differentpurposes and the lamp assembly 17, 18 can be hooked into the circuit inmany different ways. FIG. 12 shows one possible circuit arrangement inwhich the center electrode 29 and one of the contacts 28 are situated ina circuit X which is shown closed in FIG. 12 while the other contact 28and the center electrode 29 are situated in a circuit Y. In theillustrated circuit the lamp assembly is electrically connected with theleft contact 28 of FIG. 12 and with a center electrode so that wheneverthe blade 31 moves to the illustrated position where the circuit X isclosed the lamp 18 will become illuminated to indicate to the operatorthat the circuit X is closed while the circuit Y is open. This circuit Ymay simply be an open circuit so that the structure operates only toclose and open the circuit X, or the circuit Y may be a completelyindependent circuit, and the closing of this circuit will be indicatedby the extinguishing of the lamp 17. On the other hand, it is perfectlypossible to connect the lamp assembly 17, 18 into a completely separatecircuit which is simply closed and opened when an entire machine isturned on or off or which can be closed when night lights turned on soas to render the pushbutton visible at night, or any other purpose maybe served by the electrical structure, the connections of FIG. 12 beingillustrated only by way of example.

While particular embodiments of this invention have been shown anddescribed, it will be obvious to those skilled in the art that changesand modifications may be made thereto without departing from theinvention in its broader aspects and, therefore, the scope of thisinvention and the true spirit thereof shall be accordingly defined bythe appended claims.

What is claimed is:

1. In an illuminated pushbutton control device the arrangementcomprising a pushbutton having a flexible elongated side portion, saidside portion having a recess and a detent at the inner wall thereof; anda lamp holder having a flange around the periphery thereof, said flangeengaging said detent and said recess thereby capturing said lamp to saidpushbutton.

2. An illuminated pushbutton control device comprising a housing havinga longitudinal opening therethrough, electrical contacts connected toone end of said housing, a common contact, a snap acting toggle to placesaid common contact in contact with one of said electrical contacts, arotatable cam, a pawl urging said cam to rotate thereby causing saidsnap action toggle to operate, a pawl guide urging said pawl againstsaid cam, an at least partly light permeable pushbutton inserted intoone end of said housing and having an elongated end engaging said pawlguide, a compression spring biasing said pawl against said pawl guideand producing a return force on said pushbutton, a lamp assemblysubstantially stationarily arranged within said housing, means forslidably retaining said lamp assembly to said pushbutton, and means forretaining said pushbutton and said lamp assembly to said housing so asto allow longitudinal motion of said pushbutton substantially withoutmoving said lamp assembly.

3. In a switch, a switch housing, a hollow pushbutton slidable in saidswitch housing and having a front exposed end accessible to an operator,said front exposed end of said pushbutton being at least partiallylight-permeable, a lamp assembly situated in said hollow pushbutton andadapted to receive a lamp which, when illuminated, provides lightvisible through said light-permeable front end of said pushbutton, and apair of yieldable retaining means respectively carried by said switchhousing and said pushbutton and engaging said lamp assembly forretaining the latter at a given position in said switch housing duringactuation of said pushbutton while releasing said pushbutton and lampassembly therein for removal from said switch housing when the force ofthe yieldable retaining means carried by said switch housing is overcomeand releasing said lamp assembly from the interior of said pushbuttonafter the latter has been removed from said switch housing and the forceof the yieldable retaining means carried by said pushbutton is overcome.

4. The combination of claim 3 wherein said yieldable retaining meanscarried by said switch housing includes elongated electricallyconductive members engaging said lamp assembly for connecting the latterinto an electrical circuit illuminating a lamp received in said lampassembly.

5. The combination of claim 4 wherein said lamp assembly includes a lampbase having an exterior flange, one of said electrically conductivemembers of said retaining means carried by said switch housing having aspringy detent engaging said flange for yieldably preventing movement ofsaid lamp assembly outwardly from said switch housing, said lampassembly including a center contact for a lamp carried by said lamp baseand the other elongated conductive member carried by said switch housingengaging said center contact to prevent movement of said lamp assemblyinwardly.

6. The combination of claim 5 wherein said springy detent is yieldablefor selectively moving said lamp assembly out of said switch housingtogether with said pushbutton.

7. The combination of claim 6 wherein the yieldable retaining meanscarried by said pushbutton is in the form of a springy elongated wall ofsaid pushbutton capable of moving relative to the remainder of saidhollow pushbutton and having a detent engaging said flange of said lampbase for retaining said lamp assembly in said hollow pushbutton, saidswitch housing cooperating with said detent of said retaining meanscarried by said pushbutton for preventing yielding of the latter detentwhile said pushbutton is in said housing.

8. The combination of claim 3 wherein said yieldable retaining meanscarried by said pushbutton is in the form of a springy wall portionthereof capable of yielding with respect to the remainder of saidpushbutton and carrying a detent, said lamp assembly including a lampbase provided with a projection engaged by said detent for yieldablypreventing removal of said lamp assembly from the interior of saidhollow pushbutton, said switch housing cooperating with said springywall portion of said pushbutton to prevent the latter from yieldinguntil said pushbutton is removed from said switch housing.

9. In a switch, a center electrode having a bearing portion formed withan elongated groove situated in a predetermined plane, a pair ofstationary contacts respectively situated on opposite sides of saidplane, a switch blade having an edge situated in said groove andtiltable between said stationary contacts, bearing means carried by saidcenter electrode and providing a pivot axis situated substantially insaid plane and extending substantially parallel to said groove, cammeans pivotally supported by said bearing means for turning movementabout said pivot axis, an elongated snap-spring connected to said cammeans and to said blade for snapping the [latter between said stationarycontacts during turning of said cam means about said pivot axis todisplace one end of said snap-spring from one to the other side of saidplane, pawl means having a rest position situated substantially in saidplane, spring means acting on said pawl means for yieldably maintainingthe latter in said rest position thereof, a pawl guide engaging saidpawl means for guiding the latter for tilting movement to one or theother side of said plane, and a pushbutton shiftable by an operator,said guide being responsive to and arranged to transmit the motion ofsaid pushbutton to said pawl means and to place said pawl means inengagement with said cam means for tilting the latter about said pivotaxis to displace said snap-spring at its end connected to said cam meansfrom one to the other side of said plane so as to snap said blade fromone to the other of said stationary contacts, said spring-means actingon said guide and through the latter, on said pushbutton, to return thelatter and said guide to a rest position where said pawl means issituated substantially in said plane in readiness for changing theposition of said blade during the next actuation of said pushbutton byan operator.

10. The combination of claim 9 wherein said center electrode has a pairof ears formed with aligned notches which form said bearing means, saidca m means having a pair of trunnions situated in said notches to beguided for turning movement thereby and having a hollow interior and ashaft carried in said hollow interior and receiving one end of saidsnap-spring, said cam means having a pair of opposed projectionsalternately situated in the path of movement of said pawl means duringtilting of said cam means for moving said blade between said stationarycontacts.

11. The combination of claim 9 wherein said guide is hollow and has anelongated rib of V-shaped cross section having its crest situated insaid plane, said pawl means including an elongated transverse bar formedwith a V-groove receiving said rib, said spring means engaging said barof said pawl means for urging the latter against said rib of said guide.

12. In an illuminated pushbutton control device, the arrangementcomprising: a housing having a longitudinal portion therethrough, a lugdisposed within the inner diameter thereof, a pushbutton having anelongated side portion, said side portion having a longitudinal grooveextending into an inclined plane, said lug engaging said groove andinclined plane preventing said button from rotating within said housingand permitting axial motion of the button within said housing, a lampassembly and a detented lamp contact mounted in said housing, said lampassembly engaging said detented lamp contact to retain said lampassembly to said housing.

13. In a pushbutton control device, the arrangement comprising: ahousing having a longitudinal portion therethrough, a lug connected tosaid housing and dis posed within the inner diameter thereof, apushbutton having a front end accessible to an operator and having anelongated side portion, said side portion having a groove With a firstand second groove portion respectively extending in longitudinaldirection thereof and laterally offset with regard to each other, and anintermediate substantially circumferentially extending groove portion,said second groove portion being open at that end of said side portionwhich is remote from said front end to permit axial insertion into andwithdrawal of said lug from said groove, said lug normally engaging saidfirst groove portion and being locked therein to prevent rotation ofsaid pushbutton during normal use, and to permit axial motion of saidpushbutton in said housing, said pushbutton being rotatable relative tosaid housing when said lug is in said intermediate groove portion so asto permit transfer of said lug from said first to said second grooveportion for withdrawing said pushbutton from said housmg.

14. A switch according to claim 9 wherein the angular movement of saidcam means about said pivot axis is limited so as to prevent the bladesover-center position from being co-linear with said pivot axis and withthe connection between said snap-spring and said cam means whilepermitting the end of said blade remote from said groove and saidsnap-spring to pass beyond the overcenter position, whereby saidlast-mentioned end of said blade makes temporary contact with one ofsaid stationary contacts and returns to contact with the other of saidstationary contacts upon release of said pushbutton.

References Cited UNITED STATES PATENTS 2,902,559 9/1959 Morris 200683,030,465 4/ 1962 Roeser. 3,183,333 5/1965 Golbeck.

ROBERT K. SCHAEFER, Primary Examiner. H. O. JONES, Assistant Examiner.

